Bezel made with a stone seat of.8 mm square wire, no big deal. Ring
shank was made in the shape of an omega, the Greek letter, and
soldered into the bezel setting.
A modification to consider would be adding some sort of bridge from
one shoulder of the shank to the other. In essence, an added bar, or
length of the wire used as a seat, bridging that space. The reason is
that with a fully open bezel with just a wire seat, and your open
topped shank soldered to each side, any stretching force applied to
the ring can pull the sides of the bezel apart, no longer properly
fitting the stone. If the bezel and all is heavy enough, of course,
this isn’t a concern. But with lighter construction, and soft
silver, and larger cabochons, it can be an issue. That stretching
force could come just from the wearer slightly distorting the ring
shank out of round. And unlike an out of round ring shank, easily
trued back up on a mandrel, once you pull the bezel out of shape,
wider, it’s almost impossible to squeeze it back together again fully
and neatly without removing the stone, which is more work. So adding
that small reinforcing element can save you trouble down the line.